Running Calorie Burn: The Complete UK Guide
Running is one of the most calorie-intensive forms of cardiovascular exercise available. It requires no equipment beyond a good pair of trainers and can be done anywhere from city streets to Pennine trails. Understanding how many calories running burns helps with weight management, race fuelling strategies and training planning.
How Running Calorie Burn is Calculated
This calculator uses the MET (Metabolic Equivalent of Task) method, validated in the Compendium of Physical Activities (Ainsworth et al., 2011). The formula is:
Calories = MET × body weight (kg) × duration (hours)
Running METs range from 8.0 (slow jog at 8 km/h) to 16.0+ for elite racing speeds. A useful shortcut rule is that running burns approximately 1 kcal per kg per km — so a 70 kg person burns roughly 70 kcal per kilometre, regardless of pace. This rule holds well within the 8–16 km/h speed range.
Running vs Walking: Calorie Comparison
Running burns approximately twice as many calories per mile as walking. This is because the running gait requires significant muscle activation for the push-off phase and airborne period between strides. At equivalent distances, a 70 kg person running a mile burns approximately 110 kcal versus 75–80 kcal walking the same distance. However, the difference per hour is far greater: running at 10 km/h burns roughly 700 kcal/hour versus 245 kcal/hour walking at 5 km/h.
Running also produces a meaningfully larger EPOC (afterburn) effect. A 30-minute moderate-intensity run may elevate metabolism for 3–6 hours post-exercise, burning an additional 50–75 kcal. High-intensity interval running sessions can produce EPOC lasting up to 24 hours.
The Effect of Running Pace on Calorie Burn
Pace affects calorie burn per hour substantially, but the effect per kilometre is smaller than most runners expect. Consider a 70 kg runner:
- Running at 8 km/h (MET 8.0): burns 560 kcal/hour, or 70 kcal/km
- Running at 10 km/h (MET 10.0): burns 700 kcal/hour, or 70 kcal/km
- Running at 12 km/h (MET 11.5): burns 805 kcal/hour, or 67 kcal/km
- Running at 16 km/h (MET 16.0): burns 1,120 kcal/hour, or 70 kcal/km
This demonstrates why the "1 kcal per kg per km" rule holds across a wide range of paces — the body is remarkably consistent in its energy cost per unit distance when running.
EPOC: The Running Afterburn Effect
Excess Post-Exercise Oxygen Consumption (EPOC) refers to the elevated oxygen uptake and calorie burn that continues after exercise ends. Running at 70–80% of maximum heart rate produces measurable EPOC. High-intensity intervals (HIIT running) can increase total calorie expenditure by 15–20% above the running session calories alone. This calculator applies a 10% EPOC estimate — a conservative figure appropriate for moderate-intensity continuous running.
Research published in the European Journal of Applied Physiology found that a 45-minute run at 70% VO2max produced EPOC of approximately 6.5% of run calories for 2 hours post-exercise. The total afterburn is modest but meaningful when accumulated across multiple weekly sessions.
Fuelling Strategy for Running
For runs under 60 minutes, most people have sufficient stored glycogen (approximately 400–500 g in muscles and liver) to complete the session without mid-run nutrition. For runs over 60 minutes, consuming 30–60 g of carbohydrates per hour (via energy gels, sports drinks or bananas) helps maintain blood glucose and sustain pace.
The pre-run meal is important for longer efforts. Consuming 1–4 g of carbohydrates per kg of body weight 1–4 hours before a long run or race reduces the risk of glycogen depletion ("hitting the wall"). Marathon-specific carbohydrate loading — increasing carb intake to 8–12 g/kg/day for 48–72 hours before the race — is a well-evidenced strategy used by competitive runners.
Marathon and Long-Distance Calorie Requirements
A marathon (42.2 km) burns 2,500–3,500 kcal depending on body weight and pace — close to a full day's calorie intake for most people. This is why marathon runners experience "the wall" at approximately mile 20: glycogen stores are depleted, forcing the body to rely on fat oxidation, which is slower and less efficient. Well-executed race fuelling (gels every 45 minutes from mile 5) can significantly delay or avoid this.
Half marathon training plans for the London Marathon and other UK events typically involve building weekly mileage from 20 to 40+ miles per week. A runner following a 16-week marathon training plan may burn an additional 1,500–3,000 kcal per week above their baseline, representing significant calorie intake adjustments needed to avoid unhealthy weight loss and ensure adequate recovery.
Treadmill Running: Does It Burn Fewer Calories?
Treadmill running burns approximately 5–10% fewer calories than outdoor running at the same displayed speed, for two reasons. First, there is no air resistance on a treadmill — even at slow speeds, outdoor running requires slightly more energy to push through the air. Second, the moving belt provides a small propulsive assist. Sports scientists recommend setting the treadmill to a 1% incline to compensate, which makes energy expenditure equivalent to flat outdoor running at the same pace.
GPS watches used on treadmills often show inaccurate speed and distance, because GPS signal is unavailable indoors. The treadmill's built-in calorie display is typically inaccurate unless you enter your weight. This calculator applies a 5% downward adjustment for treadmill selection to account for reduced resistance.
Trail Running: Bonus Calorie Burn
Trail running on uneven terrain burns approximately 8–12% more calories than road running at the same pace. The varied surface requires more frequent micro-adjustments in balance and foot placement, engaging stabiliser muscles in the ankles, knees and hips. Trail running also typically involves more elevation gain and loss than road running, further increasing energy expenditure. This calculator applies an 8% upward adjustment for trail selection.
Heart Rate Zones and Fat Burning During Running
The "fat burning zone" concept refers to the exercise intensity at which the proportion of calories from fat is highest (approximately 60–70% of maximum heart rate). However, this is often misunderstood: at higher intensities, a greater total number of calories are burned per minute, even though the proportion from fat is lower. For weight loss, total calorie deficit is what matters, not the proportion from fat.
Heart rate zone training (Zone 2 runs at 60–70% maximum heart rate) builds aerobic base and fat-burning capacity over time, while Zone 4–5 interval training maximises calorie burn per session and produces greater EPOC. A well-rounded training plan includes both.
GPS Watch Calorie Accuracy
Consumer GPS watches (Garmin, Polar, Apple Watch, Suunto) typically show calorie estimates with an error range of 10–20%. A 2019 Stanford University study tested popular fitness trackers and found that while heart rate measurement was generally accurate, calorie estimates varied by up to 43%. Watches that incorporate heart rate data alongside pace and body weight tend to be more accurate than those using pace alone. This calculator's MET-based approach is widely validated in peer-reviewed literature and is used by exercise physiologists.
UK Running Statistics: parkrun and Couch to 5K
The UK has one of the world's most active running communities. parkrun — free, weekly, timed 5km events held in parks across the UK — attracted over 350,000 participants at its pre-pandemic peak. The NHS Couch to 5K (C25K) programme has been downloaded over 5 million times in the UK and is widely recommended by GPs as an evidence-based route into regular running. Completing C25K represents a progression from walking to running 30 minutes continuously over 9 weeks, with typical calorie burn increasing from around 150 kcal per session to 300+ kcal as running ability improves.
Injury Prevention and Calorie-Efficient Running
High weekly mileage and rapid increases in training load are the primary injury risk factors for runners. The 10% rule — increasing weekly mileage by no more than 10% per week — is widely recommended to allow musculoskeletal adaptation. Common running injuries in the UK include patellofemoral pain syndrome (runner's knee), Achilles tendinopathy, shin splints and IT band syndrome, all of which can sideline runners for weeks. Strength training (particularly single-leg exercises) and adequate rest days reduce injury risk significantly.
Frequently Asked Questions
How many calories do you burn running a mile?
A 70 kg (11 stone) person burns approximately 105–115 kcal per mile running at a moderate pace (9.7 km/h or 6 mph). Heavier runners burn more in absolute terms — a 90 kg runner burns around 135–150 kcal per mile. Faster pacing burns slightly more per mile but the difference is smaller than most people expect: at 6 mph a 70 kg person burns ~112 kcal/mile, and at 8 mph approximately 115 kcal/mile. The key difference between speeds is calories per hour, not per mile.
Does speed affect how many calories you burn running?
Speed has a larger effect on calories burned per hour than per mile. Running at 10 mph (16 km/h) burns around twice as many calories per hour as running at 5 mph (8 km/h) for the same person. However, because faster running covers more distance in the same time, the calories per mile are more similar. A useful rule of thumb: running burns approximately 1 kcal per kg of body weight per kilometre, regardless of pace.
Is running better than walking for weight loss?
Running burns approximately twice as many calories per mile as walking, making it more time-efficient for weight loss. However, running has a higher injury risk and cannot always be sustained daily. Running also produces a greater afterburn (EPOC) effect — elevated metabolism for up to 24 hours post-run. For weight loss, both are effective when combined with a calorie deficit. Running wins on efficiency; walking wins on sustainability and low injury risk.
How do you calculate running calorie burn?
The standard method uses MET (Metabolic Equivalent of Task) values: Calories = MET × body weight (kg) × duration (hours). Running METs range from 8.0 (8 km/h) to 16.0+ (16 km/h). An alternative formula is: Calories approximately equals body weight (kg) × distance (km). For example, a 70 kg runner completing 10 km burns approximately 700 kcal. This rule of thumb is accurate to within ±10% for typical running speeds.
How many calories does a marathon burn?
A marathon (42.2 km / 26.2 miles) burns approximately 2,500–3,200 kcal for most runners. For a 70 kg runner this is approximately 2,900 kcal — nearly a full day's calorie intake. A 60 kg runner burns around 2,500 kcal and an 85 kg runner approximately 3,500 kcal. Marathon runners typically experience significant glycogen depletion around mile 20 (the "wall"), requiring careful pre-race carbohydrate loading and mid-race fuelling with gels, sports drinks or bananas.
Does running on a treadmill burn fewer calories?
Treadmill running burns approximately 5–10% fewer calories than outdoor running at the same pace, because there is no wind resistance or varied terrain. Setting the treadmill to a 1% incline compensates for this difference and is widely recommended by sports scientists. Some GPS watches overestimate calorie burn by 10–20% when used on a treadmill, as GPS-based speed tracking is less accurate indoors. The treadmill's own calorie display is often inaccurate without entering your weight.